Some semiconductor devices employ silicon-on-insulator (SOI) substrate in place of conventional single layer semiconductor substrate in semiconductor manufacturing, especially in microelectronics, to reduce parasitic device capacitance such that device performance can be improved. SOI substrate includes a top silicon (Si) surface layer separated from a support or “handle” Si substrate by an insulator layer. The insulator layer includes, for example, silicon dioxide, and is usually referred to as the buried oxide (BOX) layer. Components or devices, such as transistors, are formed in the top Si surface layer and the insulator layer isolates the top Si surface layer from the support Si substrate.
The insulator layer of the SOI substrate is thermally insulative compared to semiconductor layers. Thus, as integrated circuit (IC) density grows, heat which would generally dissipate through the conventional bulk substrate will not dissipate through the insulator layer and tends to build up in the top Si surface layer. This self-heating effect of SOI substrate undesirably affects the performance and reliability of the IC. Cooling systems are applied to cool down the device. However, conventional cooling systems for SOI substrates apply by large area, i.e., cooling the entire substrate or an entire module, which results in electricity wastage.
The disclosure is directed to a programmable active cooling device for the SOI substrate that cools just the hot spots on the substrate to reduce usage of electricity and achieving cost savings.